Slime effect material
Final:



You can also make it with Principled Shader only if you like to keep things simple.

Node setup:

As mentioned above, add Principled Shader, set Subsurface Scattering to around 0.2-0.3, tweak Roughness and you are ready to go.



Scene setup:

For this setup (and reference image) you will need some strong directional light in front of your object. I've used Area Light, scaled on X axis.